基于小波阈值去噪的收缩函数改进方法  

Improved method of shrink-function based on wavelet threshold de-noising

作　　者：李骜 李一兵[1] 孟霆 叶方[1] 

机构地区：[1]哈尔滨工程大学信息与通信工程学院,黑龙江哈尔滨150001

出　　处：《计算机工程与设计》2011年第10期3450-3452,共3页Computer Engineering and Design

基　　金：哈尔滨市科技创新人才研究专项基金项目(2008RFQXG025);中央高校基本科研业务费专项基金项目(HEUCF100809)

摘　　要：经典的小波去噪方法有软阈值、硬阈值滤波两类。软阈值收缩函数滤波后信号过于平滑,而硬阈值收缩函数滤波后在信号突变处伴有吉布斯现象。因此,提出介于软、硬阈值之间的一种收缩函数,通过其对小波系数的估计,使滤波后的信号在过分平滑与边缘振荡现象之间达到合理的平衡。在分析的基础上,给出了各种方法滤波后的PSNR对比值以及图像。实验结果表明,该方法在去噪的同时既有效地消除了振荡现象,又保留了部分细节信息。Classic threshold filtering is composed of the soft threshold and hard threshold. For the soft shrink-function, the filteredsignal is excessively smooth. For the hard shrink-function, the filtered signal associated with the Gibbs phenomenon in the signal mutationafter filtering. The contraction function presented is between soft and hard. Through its wavelet coefficients modification, the filtered signal reach a reasonable balance between excessively smoothness and edge oscillation. Based on the analysis, the PSNR comparison values and the image using different filtering methods are provided. The comparative results show that the improved method elimi-nate the oscillation phenomena and retain some details effectively while remove noise from image.

关 键 词：小波变换 收缩函数 阈值滤波 峰值信噪比 多分辨率分析 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]